Not Applicable.
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Not Applicable.
i. Field of the Invention
The present invention relates to baseplates for masonry tools. More specifically, the present invention relates to a novel baseplate for masonry routers, milling machines, saws and polishing tools. These tools are used to work and finish all types of masonry and stone including, for example, marble and granite. Masonry routers or milling machines are commonly used, for example, to carve a particular edge design in a counter top. Masonry saws are used to cut masonry. Masonry polishing tools are used to finish and polish, for example, counter top edges. The baseplate of such tools is the portion of the tool that contacts the masonry or substrate upon which work is being done, excluding the blade or wheel of the tool.
ii. Description of Related Art
Masonry tools have been known in the art for a considerable time. Generally, such tools are quite heavy (for example, approximately sixty pounds) and are difficult to move across a masonry surface.
In prior art masonry tools, one approach taken to minimize this problem is to place ball casters in the baseplate of the masonry tool. For example, until recently, at least one manufacturer of masonry routers used nylon balls positioned in the support member. These balls roll across the surface of the substrate easing movement of the router. One disadvantage of this approach is that masonry fragments and dust are impressed into the ball and/or caught in the ball socket. These fragments or dust then jam the ball and prevent the ball from rolling smoothly. The fragments and dust may also become caught between the ball and the substrate surface. In such a situation, movement of the baseplate may result in the surface of the substrate being scratched. This is especially disadvantageous when working with a substrate which has a surface that is finished and polished.
One approach the prior art has taken to minimize the problems associated with the ball casters described above is to eliminate the ball casters and have a cushion of water produced under the baseplate. Pursuant to this approach, water is expelled from the baseplate and the baseplate of the tool floats across the substrate surface on the cushion of water without the use of ball casters. While this approach avoids the jamming and scratching problems described above, it does not always result in easy movement across the substrate surface. This problem is particularly pronounced when the masonry tool approaches a corner of the substrate. In such a situation, the cushion of water deteriorates and the router no longer floats across the substrate surface. Rather, the router must be dragged along with its baseplate resting directly on the substrate. This presents scratching problems and results in the router being difficult to move. The difficulty of movement is particularly problematic because it frequently occurs at a corner which often requires more attention to detail than a straight edge.
U.S. Pat. No. 5,784,789 (xe2x80x9cVargasxe2x80x9d) discloses a rotary trim saw for cutting materials in difficult to reach places. Vargas teaches that the trim saw may have a base having ball caster type wheels.
German Patent Document No. DE 3,404,555 (The xe2x80x9cGerman Disclosurexe2x80x9d) discloses an apparatus for machining a stack of metal sheets. The German Disclosure teaches that the stack of metal sheets may be held against each other and against the work table surface by hydrostatic pressure. The machine blade is surrounded by a ring with multiple nozzles. Pressurized fluid is pumped from the nozzles such that there is a clearance between the underside of the ring and the top metal sheet. The German Disclosure teaches that by holding the sheets in position in this manner, the top sheet is not damaged in the machining process.
The present invention relates to a baseplate for masonry tools that will move smoothly across a work surface under all circumstances without scratching the work surface. The invention includes a support member for moving a masonry tool over a work surface. The support member has a passageway therein with an inlet for receiving fluid and a plurality of outlets for directing fluid underneath the support member. A plurality of rotating members are mounted to the bottom of the support member for allowing the support member to move relative to the work surface. The direction of fluid underneath the support member assists in the movement of the support member relative to the work surface. Thus, the rotating members and the fluid underneath the support member cooperate to facilitate the movement of the support member relative to the work surface.
In one embodiment of the invention, the rotating members are main rotating balls mounted within sockets on the underside of the baseplate. In another embodiment, the sockets are continuously flushed with fluid which continuously cleans the sockets of debris, preventing the main rotating balls from jamming and minimizing the chances of scratching the substrate. Ball bearings may be included to facilitate the rotation of the main rotating balls. In another embodiment of the invention, the main rotating balls are combined with fluid outlets in the underside of the baseplate that produce a cushion of fluid upon which the masonry tool floats. In another embodiment, the prior two embodiments are combined; fluid outlets are positioned on the underside of the baseplate and fluid outlets are positioned in the ball sockets which are continuously flushed as described above.
In operation, the outlets directing fluid underneath the baseplate of the invention produce a cushion of fluid. Pressurized water may be used as the fluid. Much, if not all, of the weight of the masonry tool is borne by the cushion of fluid underneath the support member when the fluid cushion is present. When the fluid cushion substantially deteriorates, such as when the tool approaches a corner, much, if not all of the weight of the masonry tool is borne by the rotating members. In one embodiment these rotating members are main rotating balls located within recesses in the support member. In another embodiment, the fluid outlets are positioned within the recesses to continuously expel fluid into the recesses holding the main rotating balls. This expelled fluid continuously flushes the recesses minimizing the chance of debris being caught in the recess and/or the main rotating ball and scratching the surface of the substrate.